Adsorbents based on sustainable nanomaterials from nature have attracted significant attention and are the subject of research.
Cellulose is the most abundant renewable material found in nature which contains amorphous and crystalline domains. Cellulose nanocrystals (CNCs) are obtained by an acid hydrolysis of native cellulose using an aqueous inorganic acid like sulphuric acid. After complete (or near complete) acid hydrolysis of the amorphous sections of native cellulose, individual rod like crystallites called CNCs that are insensitive to acidic environment are obtained. This rod like structures have diameters in the range of 10-20 nm and lengths of a few hundred nanometers Acid hydrolysis of native cellulose using sulphuric acid leads to the formation of sulfate ester groups that introduce negative charges to the surface of CNCs. These negative charges on the surface of CNCs promote uniform dispersion of nanocrystals due to electrostatic repulsion in aqueous solutions.